Diaphragm type air pump



Feb. 6, 1968 R. D. BECK ET AL 3,367,561

DIAPHRAGM TYPE AIR PUMP Origianl Filed Nov. 3, 1961 2 Sheets-Sheet 1 1 i24 i ,34 5% f 23 FIG-l 3 JOHN H. 'GEIGE f ATTORNEYS Feb. 6, 1968 R. D.BECK ET AL I 3,367,561

DIAPHRAGM TYPE AIR PUMP Origianl Filed Nov. 3, 1961 2 Sheets-Sheet 2ATTORNEYS United States Patent Cfiiice 3,357,561 Patented Feb. 6, 1968 2Claims. (Cl. 230-20) ABSTRACT OF THE DISCLOSURE This disclosure relatesto a vacuum control system utilizing an electromagnetically drivenpneumatic pump means for maintaining a vacuum requirement in the system,the pneumatic pump means having an inlet housing body secured to a framemeans that carries an electromagnetic motor means that will operate acantilevered mounted armature relative to the core of the motor meanswhen the coil thereof is energized. The armature is secured to anexhaust chamber body of the pump to move the exhaust chamber bodyrelative to the inlet pump housing in order to oscillate a flexiblediaphragm interconnecting the inlet housing body and the exhaust chamberbody together. The flexible diaphragm cooperates with one of thehousings to define a pumping chamber and the pump is so constructed andarranged that the same will automatically vary its volumetric pumpingcapacity by changing the effective pumping surface area of the diaphragmeven though the diaphragm is being oscillated at a constant frequency bythe electromagnetic motor means.

This application is a divisional patent application under Rule 147 ofits copending parent patent application, Ser. No. 428,605, filed Jan.21, 1965, now Patent No. 3,255,956, which, in turn, is a continuationapplication of its copending patent application, Ser. N0. 149,990, filedNov. 3, 1961, now abandoned.

A diaphragm pump according to this invention is so constructed that itmay be driven by an electromagnetic vibrator motor in an advantageousmanner, and this pump has been combined with such a vibrator motor in anovel, useful and effective manner.

However, certain advantages of the diaphragm type air pump may be usedwhen the pump is driven by any other suitable power take off which canproduce a substantially linear reciprocating motion of the desired forceand magnitude.

An electromagnetic vibrator motor has been provided, according to thisinvention, of such construction that it can be combined with an air pumpin an adjustable manner, so the vibrator motor and the air pump may beeffectively driven by the vibrator motor.

Under certain circumstances, the resonance of the vibrator motor and theresonance of the air pump may be combined to provide an elfectivecombined action. However, under certain other circumstances, theresonance of the vibrator motor and of the air pump need not be used andmany of the advantages of this invention may nevertheless be obtained.

The air pump is particularly useful and effective when it is used toproduce a vacuum for a vacuum program system, which system requires asubstantially constant source of vacuum at a substantially regulatedvacuum pressure, and which also may require a variable capacity in thevacuum punip, so the vacuum pump can effectively maintain the desiredvacuum with automatically reduced volumetric capacity when nosubstantial volume of air movement is required in the system, and whichpump automatically can increase its volume capacity when a substantialamount of air is to be removed from the program system.

The diaphragm of this air pump is so constructed that it has arelatively large pumping area when the air pump is called upon to removea substantial amount of air from the vacuum system. The diaphragmconstruction, and the support therefor is so combined that the diaphragmcan automatically reduce its pumping area when it is called upon tomaintain a vacuum with a substantially reduced amount of volume of airremoval.

Adjustments are provided in the connections between the vibrator motorand the air pump, so the motor and air pump may be connected together inan effective manner. Such adjustments are useful whether the resonanceof the vibrator motor and of the pump are to be combined, or whether theresonance of the motor and the air pump are not to be used, and theinherent power of the motor itself is used to drive the pump withoutregard to any resonance of the two members which may be present orabsent.

Accordingly, it is an object of this invention to provide an improvedair pump having one or more of the features herein disclosed.

Another object of this invention is to provide an improvedelectromagnetic vibrator motor having one or more of the featuresdisclosed.

Another object of this invention is to provide a combinedelectromagnetic vibrator motor and air pump having one or more of thefeatures herein disclosed.

Another object of this invention is to provide a vacuum producingapparatus, which is advantageously connected with a vacuum programsystem and the like, and having one or more of the features hereindisclosed.

Another object of this invention is to provide an improved vacuumproducing method.

Another object of this invention is to provide an improved method ofproducing electromagnetic vibrating power, having one or more of thefeatures herein disclosed.

Another object of this invention is to provide an improved method ofproducing electromagnetic vibrating power to operate a pumping method,and having one or more of the features herein disclosed.

Another object of this invention is to provide a method of vacuumprogram control, and having one or more of the features hereindisclosed.

Other objects are apparent from this description and from theaccompanying drawings in which:

FIGURE 1 is a side View of the electromagnetic vibrator motor and airpump in one of the many positions in which it may be operated.

FIGURE 2 is an end view taken along line 2-2 of FIGURE 1.

FIGURE 3 is an upward view taken along the line 33 of FIGURE 1.

FIGURE 4 is a top view taken along the line 4-4 of FIGURE 1.

FIGURE 5 is a cross section taken along the line 5-5 of FIGURE 1, andshowing mainly the armature and its supporting spring structure.

FIGURE 6 is an enlarged longitudinal cross section of the air pump.

FIGURE 7 is a side view of the intake valve, and also may berepresentative of a side view of the exhaust valve.

FIGURE 8 is an enlarged cross section of a portion of FIGURE 6 andshowing a portion of the exhaust valve construction.

FIGURE 9 is a view similar to FIGURE 8 but showing the somewhat similarconstruction of the intake valve construction.

FIGURE is a diagrammatic view showing a wiring construction which may beused to energize the magnetic motor.

FIGURE 11 is a diagrammatic view showing the application of the magneticmotor and air pump to a portion of a program vacuum operated system.

FIGURE 12 is a top view of a portion of FIGURE 11.

FIGURE 13 is a cross section of a portion of another embodiment of theexhaust chamber body shown in FIG- URE 6.

Certain words of indicating direction, relative position, etc., are usedin this application for the sake of brevity and clearness ofdescription. However, such words are used mainly in connection with thedirections and relative positions shown in the drawings, and it is to beunderstood that such words are equally applicable to structures which donot have the particular direction, relative position, etc., which areshown in the drawings. Examples of such words are upper, lower,vertical, horizontal, etc.

In the drawings, a diaphragm type air pump and an electromagneticvibrator motor 22 may form a motorpump unit 23 and may have means 24 ofassembling them in appropriate relationship so the motor may drive thepump in an improved manner. However, as previously indicated, many ofthe advantages may be obtained where the drive motor may be of otherconstruction, such as a rotary type motor or any other device, fromwhich a suitable power take-otf would produce a substantially linearreciprocating motion of the desired force and magnitude.

The vibrator motor may comprise a coil 26 and a laminated, U-shaped,iron core 28, having poles 30 and 32. The motor and pump may be mountedon a base 34, which may be above, below, or to the side of the motor andpump. The motor may have a metallic armature 36, which may berectangular in shape, and relatively thin, when compared to its sidearea, as illustrated. The armature may be supported by a fiat spring 38which is mounted on the base 34 between the spring pivot supports 40 and42.

If desired, the weight of the armature, distribution of its mass, andthe rate and length of the spring 38 may be designed for mechanicalresonance with the impulse forces of the motor 22, such as at afrequency of 60 cycles per second.

Rectangular slots 44, slightly larger in width and length than the crosssection of the poles 30 and 32, are provided in the armature 36. Theseslots 44 permit the armature 36 to oscillate in and out over the corepoles 30 and 32 to provide any ampliture for the armature 36, within themaximum stroke of the pump and without interference between the armatureand the core.

The slots 44 permit operation without adjustment of the armature andcore which might be required to avoid interference which could resultfrom changes in the rate of air flow, or in fluctuations of the supplyvoltage, the net result of which might be lower output from the pump atnormal operating voltage.

Electromagnetic energy to drive the armature at 60 cycles per second maybe supplied to the core 28, FIG- URE l0, and the coil 26, by connectionto a conventional 115 volt, 60 cycle, AC power supply 46, with arectifier 48 in one side of the AC line. With suitable redesign of thearmature and spring, the motor and the pump support, the constructionmay be made to operate without the rectifier 48 at 120 cycles per secondwhen connected to a 115 volt, 60 cycle, AC power supply.

When the pump is operated at 60 strokes per second, however, springlength may be greater for a specific width and thickness of the springthan when operated at 120 strokes per second. This permits a longerstroke of the pump from a specific energy input to the coil. The loweroperating frequency also will increase pump life.

The air pump 20 may be mounted on the pump bracket 50, which is fastenedto the base 34. If desired, the bracket may be resilient and may befastened adjacent the spring pivot supports 40 and 42, and held byscrews 52.

If desired, the bracket 50 when flexible may have a mechanical resonanceequal to the impulse frequency of the motor 22, such as of approximately60 cycles per second, which serves to increase pump stroke and output.

The base 34 preferably may be rigid, to eliminate undesirable twistingof the base which might otherwise occur as the armature moves in and outpast the ends of the core.

The pump 20 may be held in a notch 54 in the end of the bracket 50 whichnotch receives the inlet conduit 56, FIGURE 6. A washer 58 may be placedaround the inlet conduit 56 and then the nut 60 may be threaded on theinlet conduit 56 to clamp the bracket 50, washer 58 and pump body 62firmly together.

The pump 20 may be connected to the armature 36 by a threaded connectingrod 64 which may be attached to the armature by means of a grommet 66which may be made of neoprene or other suitable resilient material.

The grommet 66 may be placed around the connecting rod 64 and inside theopening 68 in the narrowed circular portion 70 of the armature 36. Thegrommet 66 may be tightened to a desirable tightness by the nuts 72 and74.

The lock nut 76 may secure the threaded connecting rod 64 to the exhaustchamber body 78 of the pump 20.

Longitudinal adjustment between the motor 22 and pump 20 is thusprovided.

The grommet 66 may be used to absorb most of the .arcuate motion of theconnecting rod 64 and provide what is essentially a linear reciprocatingmotion to drive the pump for increased pump efliciency. The durometerhardnes of the grommet and the degree to which it is compressed by theconnecting rod 64 and the fastening nuts 72 and 74 may be chosen andadjusted to produce desirable pump performance. In general, the lowerthe durometer hardness and the less compressive force of the nuts 72 and74 on the grommet 66, the higher will be the pump output within thepractical limits of the assembly.

The exhaust valve assembly 86, FIGURES 6 and 8, includes a circularclamping disc 92 which can telescope into the circular recess 94 of thepump body 62. An exhaust valve retainer body 96 may be placed on theother side of the diaphragm 82. The disc 92, diaphragm 82 and retainerbody 96 may be clamped together by a tube 98 with the flange 100 at oneend and an exhaust valve seat flange 102 at the other end of tube 98.The exhaust valve assembly 86 is secured together by the tube 98 and isthreadedly secured at 104 to the exhaust chamber body 78.

The exhaust valve assembly 86 has a valve retaining or receiving groove106, FIGURE 8, which has side walls 108 and which are slightly widerthan the thickness of the exhaust valve 84. The valve seat 102 extendsleftward in FIGURE 8 slightly beyond the plane 109 of groove side wall110 a suflicient distance to cause the left edge 112 of the valve 84 tobear lightly on the side wall 108 and cause a small closure force of theside 1114 of the valve 84 against the exhaust valve seat 102.

The corners 116 and 118 may be sharp. The corner 120 may have a .005inch radius.

An annular undercut area 122 is produced between the valve seat 102 andthe groove wall 110. This area 122 reduces valve noise by permitting thevalve to contact only the small area of the valve seat 102. In addition,it provides an expansion volume at 122 for the air passing throughopenings 123 in valve disc 84, to reduce air velocity. This eliminatesmuch of the objectionable noise occurring in pumps which depend onlyupon air pressures to seat the valves.

The inlet valve 80, FIGURE 9, may be identical to the exhaust valve 84and may cooperate with groove walls 108A, 110A, valve seat 102A, etc.,which are substantially identical to correspondingly numbered parts ofFIGURE 8 and which have the suflix A omitted. However, the corner 124 ofFIGURE 8 may be sharp, Whereas the corner 124A of FIGURE 9 may have aslight radius, such as a inch radius. The openings 81 in valve disc 80may be identical with the openings 123 in valve disc 84.

The shape and dimensions of the pump body 62 have been designed for highvolumetric efliciency in comparison with the pump con-figuration and thestroke characteristics.

An example is the clearance volume provided at 94 for the clamping disc92 to clamp the diaphragm 82 and exhaust valve assembly 86.

In a typical operation of the pump 20, starting from a neutral position,as shown in FIGURE 6, with the pump being driven in a substantiallysimple harmonic motion, such as would be provided by vibrator motor 22,the force applied on the connecting rod 64 moves the diaphragm 82 andthe associated parts leftward away from the pump body 62. The pressureinside the suction chamber 125 of the pump is then reduced. This causesthe exhaust check valve 84 to seal tightly against its seat 102, and theinlet check valve 80 to move leftward away from its seat 102A and toallow air to flow through the inlet connection 56 into the pump 20. Asthe limit of the stroke is approached, its stroke velocity decreases,causing the rate of change of pressure within the suction chamber 125 ofthe pump to decrease until at the end of the leftward stroke the strokevelocity is O, the pressure drop across the inlet valve 80 is 0, and theinlet valve 80 is closed. Upon reversal of the diaphragm motion to startthe rightward stroke, resulting from the energy stored in the leafspring 38 and in the diaphragm 82, the pressure within the chamber 125of the pump increases, forcing the exhaust valve 84 to open. Air isdischarged from the tube 98 in the exhaust chamber 88, creating a slightback pressure which, in combination with the construction of the chamber88, has a muffiing effect on the exhaust noise. Air from the chamber 88then passes out through the exhaust nipple 90, where further mufliingmay be achieved by attaching to the exhaust nipple 90 a suitable lengthof flexible tubing 91. A small piece of foam rubber 93 may be used inthe tubing 91 for additional reduction of noise.

When the pump 20 is to be used as a vacuum pump only, the exhaustchamber 88A, FIGURE 13, corresponding to chamber 88 of FIGURE 6, may bemade of powdered metal 78A having density such that the desired air flowat a suitable noise reducing back pressure occurs directly through thepowdered metal wall 7 8A. The chamber 83A of FIGURE 13 may be similar inshape to the chamber 88 of FIGURE 6, with the exception that the exhaustnipple 90, pipe 91, and foam rubber 93 may be omitted, in which case theair filters out through the casing wall 78A.

In general, small air pumps can be very noisy in their operation, if notdesignated properly. In the air pump of this invention, a unique designof valving has been provided to reduce noise. Both of the valves 80 and84 are circular discs, as shown in FIGURE 7, and are retained at theirperipheries in the grooves 106 and 106A, which have been described.

In the construction shown and described herein, the valves 80 and 84seat on narrow annular seats 102 and 102A respectively, which extendleftwardly, as illustrated in the drawings, slightly beyond the plane ofthe peripheral retaining grooves 110 and 110A. The annular areas 122 and122A between the valve seats 102 and 102A and peripheral retaininggroove walls 110 and 110A are undercut for reasons described herein.

In the pump assembly, the leftwardly extended seats 102 and 102A causethe valves 84 and to assume an almost imperceptible cupped shape,thereby exerting a small closure force on seats 102 and 102A by reactionon the surfaces 112 and 114, and 112A and 114A, respectively. This makesthe valves return naturally to a closed position before, but near, theend of the pump stroke when the velocity and pressure drop across thevalves are approaching 0. In this manner, valve slap is minimized.

The undercut, annular areas 122 and 122A reduce the noise by permittingthe valves to contact only the small area of the valve seats 102 and102A. In addition, the areas 122 and 122A provide an expansion volumerespectively to reduce air velocity noise of the air passing through theopenings 81 and 123. This eliminates much of the objectionable noiseoccurring in pumps which depend only upon changes in air pressure toseat the valves.

Another advantageous feature of the pump 20 and vibrator motor 22 is theunique dynamic operating characteristic which can be obtained by meansof the angled pole faces 150 and 152. Such angled faces are provided onboth of the poles 30 and 32. These angled pole faces of the laminatedcore 28 cooperate with the amount of concavity of the pump body 62 atthe conical portion 154. The concavity 154 may be 15, more or less, withrespect to the normal central perpendicular position of the diaphragm82, as illustrated in FIGURE 6. With the pump operating under minimumair flow, or no flow conditions, with a maximum pressure differential orvacuum across suction chamber 125 to the exhaust chamber 88 of the pump,the resilient, flexible diaphragm 82 will be forced rightwardly againstthe pump body concave or conical surface 154 at the diaphragm periphery.The effects of this are: (l) the effective working area of the diaphragm82 is reduced as the pressure differential increases; (2) the center ofoscillation of both the diaphragm 82 and of the armature 36 are movedrightwardly, that is, away from the core pole faces and 152; and (3) thechanging armature position results in an increase in the average airgap, the magnitude of which is determined by the angularity of the polefaces 150 and 152, resulting in a reduction in the electromagnetic forceof attraction. The combination of these three effects provides a uniquemethod of limiting the maximum pressure dif ferential withoutsacrificing performance at the maximum flow conditions when asubstantial amount of air is required to be moved away from the vacuumprogram system and the like at a much lower pressure differential. Inaddition, the magnitude of the maximum pressure differential can bevaried as desired over a wide range, by positioning the armature withrespect to the core by adjusting the position of the nuts 72 and 74, andthe position of the rod 64 and the nut 76, to provide a smaller orlarger air gap, and a corresponding smaller or larger pumping capacity,as desired.

When greater air flow volume is required to be removed from the vacuumsystem, the reduced pressure differential across the pump automaticallyallows the diaphragm 82 to have a greater working area because itoperates farther away from the concavity 154. Also it has a moreleftward center of oscillation with a reduced average air gap betweenthe armature 36 and the core 28, which results in a greater or strongerelectromagnetic force and a larger stroke.

In this manner, the relationship of the concavity 154 with respect tothe diaphragm 82 provides automatic reduction of pump stroke after thedesired vacuum or pressure differential has been obtained by the contactof a portion of the diaphragm 82 with the concavity 154. However, whenair in larger volume is desired to be removed from the system, when thevacuum has been partially reduced in the system, then the diaphragm 82operates farther from the concavity 154, to provide a larger effectivediaphragm area and also a longer stroke of the diaphragm, to produce agreater volumetric pumping power in the pump 20.

In FIGURES 11 and 12 a program system 159 is shown wherein a card orfilm 160 passes over a smooth surfaced block or reading head 162 with asmooth reading surface 164.

The reading head 162 has one or more discharge passageways 166 withdischarge ports 168 at the reading surface 164. The dischargepassageways 166 are connected by resilient plastic pipes 167, ifdesired, respectively with one or more vacuum motors or actuators 170which operate various levers, switches, etc., of a machine such as awashing machine.

The reading head 162 has one or more intake pass-ageways 172 which haveintake or suction ports 174 at the reading surface 164. The passageways172 may merge into a common suction passageway or manifiold 176 which isconnected by a resilient plastic pipe 177, if desired, to the intake 156of the motor pump unit 23, such as disclosed in FIGURES 1-10 and 13.

The card or film 160 may have a plurality of indentations or closedinverted channels 176 which bridge two or more ports such as ports 168and 174, as illustrated in FIGURES 11 and 12. The margins of theindentations 176 form a seal with the reading surface 164 and form afluid connection between the respective vacuum actuator 170 and thesource of vacuum or motor pump unit 23.

The indentations 176 in each of the rows 178 and 180 are sufficientlyclose to maintain a substantially constant bridging action between theports 168 and 174 as the indentations pass over the ports. This isaccomplished by making the space between the indentations of theparticular row narrower than the diameter of the ports, if desired.

When a particular vacuum actuator 170 has been energized by beingsubjected to a vacuum to pull on its respective diaphragm 171, suchactuator 170 may be deenergized by breaking the vacuum in its respectivepassageway 166 to allow its diaphragm 171 to be pulled out by combinedatmospheric and spring action or the like. The vacuum may be broken bycausing a hole 182, in the film 160, to pass over the respective port168. This permits atmospheric air to enter the respective passageway 166to allow the respective diaphragm to move outwardly.

Ordinarily the corresponding suction port 174, pposite the hole 182, isnot uncovered so the film 160 prevents the breaking of the vacuum in thepassageway or manifold 176 which is connected to the vacuum pump 20.

Because of the relatively small size of the vacuum chambers in actuators170 and of the respective passageways 166, only a small volume of air isintroduced into the system through the hole 182. In view of this thepump ordinarily has long periods of time when it operates to maintain avacuum without pumping any material amount of air. The ability of thediaphragm 82 to reduce its eifective pumping area by contact with theconcave wall 154 permits the pump 20 to operate with a very small powerconsumption.

For a control system for a domestic automatic clothes washing machine,the following sizes more or less have been found satisfactory.

Diaphragm diameter AA=% Diameters of valves and 82,

Diameters of valve holes 81,

Other parts of the pump, etc., may be of proportional size.

It is thus to be seen that new and useful constructions and methods havebeen provided.

While the form of the invention now preferred has 'been disclosed asrequired by statute, other forms may be used, all coming within thescope of the claims which follow.

What is claimed is:

1. In combination: a vacuum program control system having a variable airvolume removal requirement; an electromagnetically driven vacuum airpump connected to said system, said pump having a housing and a flexiblediaphragm cooperating together to define a pumping chamber, saiddiaphragm being oscillated at a constant frequency relative to saidhousing by an electromagnetic motor means to cause said air removal forsaid system; and means automatically varying the air volume removalcapacity of said pump in response to the air volume removal requirementof said system by changing the effective pumping surface area of saiddiaphragm even though said diaphragm is still being oscillated at saidconstant frequency by said motor means.

2. A method of maintaining a vacuum in a vacuum program control systemhaving a variable air volume removal requirement which comprisesmaintaining said vacuum by a pumping action of an electromagneticallydriven diaphragm pump that has its diaphragm oscillated at a constantfrequency by an electromagnetic motor means, and automatically varyingthe volumetric capacity of said pumping action in response to saidvariable air volume removal requirement by changing the effectivepumping surface area of the diaphragm of said pump even though saiddiaphragm is still being oscillated at said constant frequency by saidmotor means.

References Cited UNITED STATES PATENTS 1,265,928 5/1918. McClymont 23013 1,394,887 10/1921 Cooper 230-20 2,018,111 10/1935 Ba'bitch 2302,471,796 5/1949 Thiberg 230---162 2,890,810 6/1959 Rohling 2301703,039,399 6/1962 Everett 103-38 X FOREIGN PATENTS 956,466 8/ 1949France. 990,042 5/ 1951 France.

DONLEY I. STOCKING, Primary Examiner.

LAURENCE V. EFNER, Examiner.

W. L. FREEH, Assistant Examiner.

